Method and apparatus for sorting heterogeneous material

ABSTRACT

A system is provided for the identification and separation of heterogeneous material, the system comprising: a hyperspectral identification system for capturing spectra of material; a computer receiving and analyzing data from the hyperspectral identification system and selecting desired materials from the heterogeneous materials; and an ejection system, whereby the desired materials are ejected from the system.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/259,584, filed on Apr. 23, 2014, which is a continuation of U.S.application Ser. No. 12/620,909, filed on Nov. 18, 2009. U.S.application Ser. No. 12/620,909 claims the benefit of U.S. ProvisionalApplication No. 61/115,771, filed Nov. 18, 2008. These applications areherein incorporated by reference in their entirety for all purposes.

FIELD OF THE INVENTION

The invention relates to methods and apparatus for sorting heterogeneousmaterial, and more particularly, to an automatic sorting systems for theidentification and separation of such material.

BACKGROUND OF THE INVENTION

Recycling of post consumer and industrial material requires thatcomposite materials be sorted and separated according to color,composition, shape, size, or any of several criteria. Such sorting hastraditionally been done manually, wherein sorters visually identifyobjects to be sorted, and transfer them from one conveyer belt toanother running parallel to the first. This is labor intensive andexpensive. Automated systems have been developed to replace thistraditional hand sorting. In such systems, materials are identified byconventional optical scanner and are transferred from a first conveyerby means of a mechanical or pneumatic force to a second conveyer. Suchsystems typically are imprecise in their sorting, allowing materials tobe mixed, which must then be resorted before pelletization. This lack ofprecision is due both to the optical scanning mechanism, and theimprecise mechanical and pneumatic sorting mechanism.

Known optical sorting techniques carry materials on a conveyor orvibratory deck and then rely on air jet propulsion methods and or fingerpush methods that lift or push desired picked materials past an outboardbarrier. Unselected items typically fall off the end of the opticsconveyor or shaker deck and often dropped on a conveyor below that wouldtransport that material to another optical system where the processoccurs again. The selected ejected items that have been propelled eitherland on another belt or vibratory conveyor and deposited in a holdingbunker often with some type of post sorting to qualify the material iscorrectly identified. Such a system requires extensive room, bothhorizontally and vertically to allow for conveyers and dropping of thematerials.

What is needed therefore is a means for automated sorting heterogeneousmaterial with high degrees of precision.

SUMMARY OF THE INVENTION

One embodiment of the present invention provides a system for theidentification and sorting of heterogeneous material, the systemcomprising: a hyperspectral identification system for capturing spectraof material, the hyperspectral identification system comprises at leastone hyperspectral camera the hyperspectral camera receiving a pluralityof selected spectral bands of infrared and visible light correspondingto spectral signatures of target materials to be identified if presentin the heterogeneous material; the camera disposed proximate to avisible or infrared light source, the light source and the at least onehyperspectral camera are disposed on the same side of a stream of theheterogeneous material; a solid belt having first and second ends, thebelt running beneath the hyperspectral identification system and uponwhich the heterogeneous material is conveyed from the first end to thesecond end, the belt traveling at a preset rate, the hyperspectralidentification system being disposed over the second end of the belt; acomputer receiving and analyzing data from the hyperspectralidentification system and selecting materials of a first user definedcategory from the materials; and an ejection system disposed immediatelyafter the second end of the belt, whereby the desired materials areseparated from the heterogeneous material, the ejection system beingtriggered by the computer at a preset time delay equal to the distancebetween the camera and the ejection system divided by the rate of travelof the belt.

A further embodiment of the present invention provides such a systemfurther comprising a conveyer to deliver the heterogeneous material tothe system.

Yet another embodiment of the present invention provides such a systemfurther comprising a receiving system, whereby the materials of a firstuser defined category are segregated and collected.

A yet further embodiment of the present invention provides such a systemfurther comprising an array of lights disposed proximate to thehyperspectral identification system.

Even another embodiment of the present invention provides such a systemwherein the lights have a wavelength suitable for hyperspectral imaging.

An even further embodiment of the present invention provides such asystem wherein the hyperspectral identification system is configured tocollect spectral and spatial information from heterogeneous materialentering the system, store the spectral and spatial information asimages.

Still another embodiment of the present invention provides such a systemwherein the computer comprises software configured to compare the imagesto images stored in a library of images.

A still further embodiment of the present invention provides such asystem wherein the ejection system comprises a plurality ofindependently controlled air nozzles disposed beneath the material, anda blower hood disposed above the material, the blower hood providing aair current whereby the selected material is blown out of a dischargeport.

Yet another embodiment of the present invention provides such a systemwherein the heterogeneous materials comprise waste and recyclablematerials.

A yet further embodiment of the present invention provides such a systemwherein the computer can select a plurality of user defined materials.

Still yet another embodiment of the present invention provides such asystem wherein the ejection system comprises a mechanical ejector.

A still yet further embodiment of the present invention provides such asystem wherein the ejection system comprises a fluid jet.

Still even another embodiment of the present invention provides such asystem wherein the fluid jet is a water jet.

One embodiment of the present invention provides a method for sortingheterogeneous material, the method comprising: reflecting visible orinfrared light from the surface of the heterogeneous material disposedon a conveyer; conveying the heterogeneous material at a predeterminedrate through a hyperspectral imager; generating hyperspectral images ofthe heterogeneous material by receiving a plurality of selected spectralbands of infrared and visible light corresponding to spectral signaturesof target materials to be identified if present in the heterogeneousmaterial as the heterogeneous material passes on the conveyer beneaththe hyperspectral imaginer; comparing the hyperspectral images of theheterogeneous material to hyperspectral images of known materials;identifying the target materials; after a preset time interval from theidentifying the target material, the interval equal to the distancebetween the hyperspectral imager and a separating system divided by thepredetermined rate, physically isolating target material from theheterogeneous material by separating the selected material from theheterogeneous material as it leaves the conveyer immediately after thehyperspectral imager.

Another embodiment of the present invention provides such a methodfurther comprising illuminating the heterogeneous material to optimizethe hyperspectral images.

A further embodiment of the present invention provides such a methodwherein the hyperspectral images comprise spectral and spatial data forarticles within the heterogeneous material.

Even another embodiment of the present invention provides such a methodwherein the heterogeneous material comprises waste material andrecyclable material in combination.

The features and advantages described herein are not all-inclusive and,in particular, many additional features and advantages will be apparentto one of ordinary skill in the art in view of the drawings,specification, and claims. Moreover, it should be noted that thelanguage used in the specification has been principally selected forreadability and instructional purposes, and not to limit the scope ofthe inventive subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front perspective drawing illustrating a system for theseparation of heterogeneous material configured in accordance with oneembodiment of the present invention.

FIG. 2 is a rear perspective drawing illustrating a system for theseparation of heterogeneous material configured in accordance with oneembodiment of the present invention.

FIG. 3 is a rear perspective drawing illustrating an optical scanner ofa system for the separation of heterogeneous material configured inaccordance with one embodiment of the present invention.

FIG. 4 is a side perspective drawing illustrating a blower hoodconfigured for use in a system for the separation of heterogeneousmaterial configured in accordance with one embodiment of the presentinvention.

FIG. 5 is a front perspective drawing illustrating a conveyer, air knifeand ejector configured for use in a system for the separation ofheterogeneous material configured in accordance with one embodiment ofthe present invention.

FIG. 6 is a bottom, exploded perspective drawing illustrating an airknife and ejector configured for use in a system for the separation ofheterogeneous material configured in accordance with one embodiment ofthe present invention.

FIG. 7 is a top, exploded perspective drawing illustrating an air knifeand ejector configured for use in a system for the separation ofheterogeneous material configured in accordance with one embodiment ofthe present invention.

DETAILED DESCRIPTION

In one embodiment of the present invention, a system is provided havinga hyperspectral identification system and a positively sorted airejector.

In one such embodiment, illustrated in FIGS. 1 and 2, a conveyer 1carries material to a identification camera enclosure 4. Theidentification camera enclosure 4 encloses a camera 6 disposedproximately to an array of lights 5, highlighting the target area forthe camera 6. In such a system, the camera 6 is a hyperspectral camera.Hyperspectral cameras and sensors such as those employed in the oneembodiment of the present invention collect and then combine spatial andspectral information as a set of ‘images’. In one embodiment,illustrated in FIG. 3, the camera 6 may be mounted on camera mountingbrackets 10.

Each image, thus generated, represents a range of the electromagneticspectrum and is also known as a spectral band. These ‘images’ are thencombined and form a three dimensional hyperspectral cube for processingand analysis.

Hyperspectral sensors also referred to as “imaging spectroscopy” look atobjects using a vast portion of the electromagnetic spectrum. Certainobjects leave unique ‘fingerprints’ across the electromagnetic spectrum.These ‘fingerprints’ are known as spectral signatures and enableidentification of the materials that make up a scanned object.Identification systems, can compare the spectral “fingerprint” of asample with an unknown composition to a known spectra from a library ofknown exemplars.

Hyperspectral cameras of one embodiment of the present invention,utilize visible light, ultraviolet, and infrared spectral imaging thatutilizes spatial information provided by the hyperspectral image.Infrared is, in such an embodiment, the primary band utilized inidentifying individual recyclable commodities encompassing sometimes avariety of spectral signatures including color for sorting and commoditysegregation purposes. One skilled in the art will appreciate thatembodiments of the present invention may be used in sortingheterogeneous materials in other fields including but not limited toagriculture, medicine, and industrial applications.

Hyperspectral data, collected by the camera 6, comprises a set ofcontiguous bands. In one embodiment of the present invention, this iscollected by a single sensor, interfaced with an ejection method thatresides within its field of vision and then used to select the desireditem. This is in contrast to conventional multispectral techniques,where a set of optimally chosen spectral bands that are typically notcontiguous and need to be collected from multiple sensors. Thiscollection of spectral data is valuable in improving the accuracy of theidentification, and is employed in various embodiments of the presentinvention. A single sensor, in one embodiment of the present invention,performs all the following tasks: Identify items searched for in a largearea; searching for multiple items at the same time; identifying itemsby composition and color all with a higher degree of positiveidentification. Thus a single system may be programmed to sort allcommodities required by a user.

One embodiment of the present invention provides a system equipped withWedge Jet style high flow ejection air nozzles 17 and high speed realtime computer interfaces thus providing an ejection method capable ofpropelling desired items into an elevated air conveyance system enablingmultiple units to be orientated on a straight line.

A straight line orientation enables optical sorting systems to beinstalled in a smaller area with no vertical grade differential, thusenabling the simple retrofit of existing manual sorting lines withoptical automatic sorters with minimal site work. Such an embodimentalso enables new systems to be engineered into a much smaller footprintthan existing traditional saw tooth designs which require elevationconsideration. A system design configured according to one embodiment ofthe present invention and illustrated in FIGS. 1 and 2 provides anaccelerator rubber belt feed conveyor 1 of varying widths traveling at arate of between 200 to 600 feet per minute. A light bar system 5 shinesa high intensity light down on the belt where the hyperspectral imagingcamera 6 collects its data. The camera 6 collects that data and feeds ahigh speed Lenox computer system or other suitable computer system 3that has been programmed to receive this data and then provide outputsignals timed with the ejector nozzles 17 to eject desired product.Immediately after the discharge of the accelerator conveyor 1 isdisposed an air knife 2 that helps to levitate materials and decreasesthe likelihood of material lodging between the accelerator belt 1 andmanifold ejector plate 14. The manifold ejection plate 12 houses thewedge jets 17 and enables those jets 17 to be directed to optimal lift.The wedge jets 17 also referred to as vortex, Typhoon, Hurricane orFixed Flow Air Nozzles are fast acting, resistant to plugging anddeliver a high velocity directed air flow that then expands to an 8″diameter air flow. A venturie effect delivered by this style ejectionjet positively holds the ejected item within its air flow decreasing thelikelihood of the item colliding with competitive items in the air anddiscouraging turbulence. The additional force generated by these jets 17propels the picked items into a receiving hood 7 area located above theaccelerator belt 1. This receiving hood system 7 is fitted with a highvelocity fan type blower 8 that then pushes the selected items towardthe collection point 9 at a 90 degree angle. In an alternativeembodiment, the ejection system can be configured with at least oneflipping lever or other mechanical device whereby desired material ispushed or otherwise segregated. Negative materials not selected continuedown the ejector plate 12 and are deposited on another acceleratorconveyor (not shown) upon which non-selected materials move in series toadditional optical system where another desired item can be sorted andremoved from the waste stream. In such an embodiment, each opticalsorter may be deployed in line with the previous sorter in a very tightconfiguration with no change in elevation. The evacuation fan within thecollection hood also develops a venture effect that helps to draw lightfractional items into its air stream enhancing the collection rate ofejected selected items. An evacuation conveyor could also be positionedin this location and would deliver similar results.

A further embodiment provides an accelerator conveyor enabling thespreading out of materials, a hyperspectral imaging camera designed topositively identify about approximately 100% of the desired item (forexample, a recyclable material or other component of a heterogeneousmaterial), items, air nozzle cannons with fast acting solenoid airvalves which react to information provided by imaging camera designed tolift desired fractional recyclable material.

Yet another embodiment provides an air conveyance system which developsa Venturi effect drawing in the previously lifted desired items andevacuating those items to a holding bin.

The foregoing description of the embodiments of the invention has beenpresented for the purposes of illustration and description. It is notintended to be exhaustive or to limit the invention to the precise formdisclosed. Many modifications and variations are possible in light ofthis disclosure. It is intended that the scope of the invention belimited not by this detailed description, but rather by the claimsappended hereto.

What is claimed is:
 1. A system for the identification and sorting ofheterogeneous material, the system comprising: a hyperspectralidentification system for capturing spectra of material, saidhyperspectral identification system comprises at least one hyperspectralcamera said hyperspectral camera receiving a plurality of selectedspectral bands of infrared and visible light corresponding to spectralsignatures of target materials to be identified if present in saidheterogeneous material; said camera capturing hyperspectral imagescomprising spectral and spatial data for articles within saidheterogeneous material; said camera disposed proximate to a visible orinfrared light source, said light source and said at least onehyperspectral camera are disposed on the same side of a stream of saidheterogeneous material; a solid belt having first and second ends, saidbelt running beneath said hyperspectral identification system and uponwhich said heterogeneous material is conveyed from said first end tosaid second end, said belt traveling at a preset rate, saidhyperspectral identification system being disposed over said second endof said belt; a computer receiving and analyzing data from saidhyperspectral identification system and selecting materials of a firstuser defined category from said materials; and an ejection systemdisposed immediately after said second end of said belt, whereby saiddesired materials are separated from said heterogeneous material, saidejection system being triggered by said computer at a preset time delayequal to the distance between said camera and said ejection systemdivided by the rate of travel of the belt.
 2. The system according toclaim 1, further comprising a conveyer to deliver said heterogeneousmaterial to said system.
 3. The system according to claim 1 furthercomprising a receiving system, whereby said materials of a first userdefined category are segregated and collected.
 4. The system accordingto claim 1 wherein said hyperspectral identification system isconfigured to collect spectral and spatial information fromheterogeneous material entering said system and store said spectral andspatial information as images.
 5. The system according to claim 1wherein said ejection system comprises a plurality of independentlycontrolled air nozzles disposed beneath said material, and a blower hooddisposed above said material, said blower hood providing an air currentwhereby said selected material is blown out of a discharge port.
 6. Thesystem according to claim 1 wherein said heterogeneous materialscomprise waste and recyclable materials.
 7. The system according toclaim 1 wherein said computer can select a plurality of user definedmaterials.
 8. The system according to claim 1 wherein said ejectionsystem comprises a mechanical ejector.
 9. The system according to claim1 further comprising an array of lights disposed proximate to saidhyperspectral identification system.
 10. The system according to claim 9wherein said lights have a wavelength suitable for hyperspectralimaging.
 11. The system according to claim 9 wherein said computercomprises software configured to compare said images to images stored ina library of images.
 12. The system according to claim 1 wherein saidejection system comprises a fluid jet.
 13. The system according to claim12 wherein said fluid jet is a water jet.
 14. A method for sortingheterogeneous material, said method comprising: reflecting visible orinfrared light from the surface of said heterogeneous material disposedon a conveyer; conveying said heterogeneous material at a predeterminedrate through a hyperspectral imager; generating hyperspectral images ofsaid heterogeneous material comprising spectral and spatial data forarticles within said heterogeneous material by receiving a plurality ofselected spectral bands of infrared and visible light corresponding tospectral signatures of target materials to be identified if present insaid heterogeneous material as said heterogeneous material passes onsaid conveyer beneath said hyperspectral imaginer; comparing saidhyperspectral images of said heterogeneous material to hyperspectralimages of known materials; identifying said target materials; after apreset time interval from said identifying said target material, saidinterval equal to the distance between said hyperspectral imager and aseparating system divided by the predetermined rate, physicallyisolating target material from said heterogeneous material by separatingsaid target material from said heterogeneous material as it leaves saidconveyer immediately after said hyperspectral imager.
 15. The methodaccording to claim 14 wherein said heterogeneous material compriseswaste material and recyclable material in combination.